Grounding Questions

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Grouch1980

Senior Member
Location
New York, NY
Hey guys,
I have several grounding questions, if you can please help...

1) If you see the detail that I copied here, it shows GEC taps on the top connecting to a grounding bus bar, and the GEC's on the bottom connecting to the grounding electrodes. Where I highlighted in red, shouldn't this be a 3/0 copper ground wire as well? To me it doesn't seem to comply with section 250.66(A), where the wire doesn't have to be larger than #6 AWG. Or does it?
Grounding Detail.jpg
2) In the diagram here, this is from the 2017 NEC handbook. The 350 kcmil conductors at the top / line side are the service entrance conductors. The #3 and #3/0 wires tapping from the 350 kcmil conductors, are those considered service entrance conductors as well? or are they called S.E.C. taps? or just S.E.C.'s?

SECs.jpg
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
GECs to only rods or other made electrodes are not required to be larger than #6 cu, or #4 cu for Ufer electrodes.
 

Barney B

Senior Member
Location
Hurst, TX
Occupation
Electrical Instructor/Trainer
Hey guys,
I have several grounding questions, if you can please help...

1) If you see the detail that I copied here, it shows GEC taps on the top connecting to a grounding bus bar, and the GEC's on the bottom connecting to the grounding electrodes. Where I highlighted in red, shouldn't this be a 3/0 copper ground wire as well? To me it doesn't seem to comply with section 250.66(A), where the wire doesn't have to be larger than #6 AWG. Or does it?
View attachment 2562108
2) In the diagram here, this is from the 2017 NEC handbook. The 350 kcmil conductors at the top / line side are the service entrance conductors. The #3 and #3/0 wires tapping from the 350 kcmil conductors, are those considered service entrance conductors as well? or are they called S.E.C. taps? or just S.E.C.'s?

View attachment 2562110
(1) This is the sole connection to a rod electrode and does not extend to any other electrode. Thus, it qualifies under 250.66(A).
(2) These are SECs. See the definitions for SECs in Art. 100.
 

Grouch1980

Senior Member
Location
New York, NY
Just a follow up to my first question in post #1. Say you don't have GEC taps. All you have is the GEC from the Service Switch to the ground rod. Does 250.66(A) still apply, where a #6 is the max conductor size that is needed?
 
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